December 09, 2006
Bioengineered Yeast Tolerates Higher Ethanol For Biomass Energy Use

Some MIT researchers have developed a yeast strain that can continue to produce ethanol up to a much higher concentration of ethanol.

The work by MIT chemical-engineering professor Gregory Stephanopoulos and his colleagues focuses on the second part of this process: fermenting sugars to make ethanol. The yeast strain they made can tolerate ethanol concentrations as high as 18 percent--almost double the concentration that regular yeast can handle without quickly dying. In addition, the new strain makes about 20 percent more ethanol by processing more of the glucose, and it speeds up fermentation by 70 percent.

The research was done on a lab strain of yeast and still would need to be repeated on an industrial strain to be useful in a production environment. This capability, added to an industrial yeast strain, offers a couple of advantages. First, it reduces the capital cost of sugar fermentation to produce ethanol because the same sized fermenting tank can produce more yeast in the same amount of time. Second, the energy cost of separating ethanol from water at the end of the fermentation is lowered because the final solution has more ethanol and less water.

These researchers also want to genetically engineer the yeast to break down cellulose into simple sugars. Then yeast could perform the two biggest steps in making ethanol from biomass.

I think these results also raise the more distant prospect of highly automated home biomass ethanol fermenters. Take your bush, tree, and lawn cuttings, dump them into a home fermenter with genetically engineered organisms, and out comes ethanol for your car. Nanotech materials serving as catalysts might even some day replace the yeast.

I can also imagine an ethanol production system with nanotech membranes to produce ethanol that automatically shoves each ethanol molecule into a separate pure ethanol partition on the other side of the membrane from the sugars.

Ethanol is less than ideal as a liquid fuel because it has much less energy per gallon than gasoline. A bioengineered microorganism that produced non-oxygenated hydrocarbons from sugars would be even more attractive.

Share |      Randall Parker, 2006 December 09 02:10 PM  Energy Biomass


Comments
Bob Badour said at December 10, 2006 11:32 AM:

Alcohol tolerant yeast is nothing new. I wonder if this new yeast tolerates higher temperatures too? It sounds to me that all the researchers managed to do was select "vodka yeast" or "turbo yeast" out of a random population of wild yeasts.

Saying that the new yeast tolerates twice the alcohol of regular yeast tells me they are comparing against a bread, beer or wild yeast. Champagne yeast tolerates up to 16% alcohol quite readily.

I wonder why the focus on ethanol in the first place. Fermentation produces a lot of C02. I wonder whether another technology might produce a different carbon waste that sequesters the carbon or turns more of it into burnable fuel?

JMG3Y said at December 10, 2006 1:47 PM:

An interesting comment on The Oil Drum with regard to enhancing the ethanol production of microbes:

http://www.theoildrum.com/story/2006/12/8/0547/13517#59

Googling the name of that researcher (Ingham) or that organism (Klebsiella planticola) brings up the remnants an intense debate that echoed around the Internet and across continents.

Paul Dietz said at December 16, 2006 4:17 AM:

I wonder why the focus on ethanol in the first place. Fermentation produces a lot of C02. I wonder whether another technology might produce a different carbon waste that sequesters the carbon or turns more of it into burnable fuel?

Carbohydrates can be reduced to hydrocarbons by reaction with hydrogen on Raney nickel catalysts. Some additional steps can be used to join the carbon chains of two sugar molecules so the resulting hydrocarbons have sizes suitable for transportation fuels (hydrogenating ordinary sugars alone will make pentane or hexane, which are too volatile). The waste of this process is water; all the carbon ends up in the fuel.

The hydrogen does have to be provided, but you can view this as an opportunity to add another energy input to the biomass stream, so a given quantity of biomass can provide more liquid fuel energy.

TTT said at December 19, 2006 6:13 PM:

Randall,

So, correct me if I am wrong :

1) Corn is not efficient for Ethanol, but a lot of progress is being made towards cellulose (switchgrass, corn husks, etc.) which could increase gallons per acre of Ethanol.
2) But you feel this is still bad due to the amount of land this could consume, and all the forests that would be cut down, etc. So you *dont* want a cellulose breakthrough.
3) You advocate wind, solar, etc. to meet our energy needs. I agree that these would be good as they can be constructed over unusable land. But this still replaces just electricity, not liquid fuel for cars, correct? This can only be used for cars if electric cars become cost efficient enoguh to displace current gasoline cars.
4) So you are hoping that solar/wind cost efficiencies happen before someone makes a cellulostic breakthrough to improve biomass efficiency. But either way, this also means oil and coal are going to be greatly displaced by 2015 or 2020. The countries that depend on oil exports for most of their economy are thus doomed within 10-14 years anyway. Is this a correct conclusion based on what you have said so far?

Randall Parker said at December 19, 2006 7:43 PM:

TTT,

I expect the breakthroughs in cellulosic technologies before we get all electric vehicles in significant number. I expect a continued rise in production of ethanol. But I expect land limitations for biomass ethanol production capacity to prevent ethanol from becoming more widely used than gasoline.

Electricity from solar and nuclear could displace natural gas and coal for electric power generation. That'd make the environment cleaner even if the electricity was not used for transportation. Also, that'd free up natural gas for conversion into liquid fuels.

The problem with nuclear is that it costs more than coal unless coal generators are required to sequester carbon dioxide. See my post US Corporate Support For CO2 Emissions Capture Increasing and the comments section where Philip Sargent of Cambridge Energy Research Associates lays out the economics of coal versus nuclear electric power. In a nutshell: Coal without CO2 sequestration is cheaper than nuclear. Except one cleaner form of coal is about the same as nuclear. But coal with CO2 sequestration is more expensive than solar.

I expect a big increase in the land used for agriculture due to biomass and increased demand for meat from populations experiencing rising affluence. But I hope at some point advances that lower the costs of nuclear and solar will stop and reverse that trend.

I also expect advances in battery technology to eventually reduce the demand for liquid fuel for transportation.

I want to see bigger government funding of nuclear, photovoltaics, and battery research so that we slow and stop the trend toward biomass sooner than would otherwise be the case.

TTT said at December 19, 2006 7:53 PM:

Randall,

OK, that makes sense.

>>But I expect land limitations for biomass ethanol production capacity to prevent ethanol from becoming more widely used than gasoline.

In the US perhaps, but what is to stop an export-hungry Brazil from chopping down thousands of square miles of rainforest to grow cellulose-ethanol crops? If China cut a deal with Brazil to do this, Brazil may throw rainforest preservation concerns aside.

>>>Also, that'd free up natural gas for conversion into liquid fuels.

Is it expensive or cheap to get natural gas to become a liquid that can be used in cars. If this is a large obstacle, then this jump may not occur, and hence Ethanol would barrel forward.

>>I also expect advances in battery technology to eventually reduce the demand for liquid fuel for transportation.

But this is still later than the Cellulose ethanol breakthroughs, which still mean a large Ethanol phase would exist for a while, with all associated land use.

>>I want to see bigger government funding of nuclear, photovoltaics, and battery research so that we slow and stop the trend toward biomass sooner than would otherwise be the case.

Agreed, but it appears that no matter what, either way, oil consumption will drop and countries that rely on oil exports are going to be the biggest losers of all. There are too many forces working against oil, whether cellulose ethanol, nuclear, photovoltaics, batteries, etc. Only one or two of these need to have a breakthrough for oil to get displaced. Would you agree?

Randall Parker said at December 19, 2006 9:35 PM:

TTT,

Yes biomass threatens rainforests. No doubt about it.

Natural gas conversion to liquid: It is my understanding this is already happening. I do not know much about the economics of it.

Yes, we are going to go thru an ethanol phase. Cellulosic technology will increase yield per acre. But since it will eventually lower costs it will drive up the demand so much that I expect it will increase total acreage used to make biomass ethanol.

A drop in oil consumption: It depends on alternatives becoming cheaper. The major liquid fuel alternative contenders are coal liquification, oil shale extraction, and biomass ethanol. But breakthroughs in battery technology would bring all the electric power sources into competition with oil. I believe the unseating of oil (short of a worldwide Hubbert's Peak) requires battery technology to bring in all the electric power sources as competition to liquid fuel.

TTT said at December 20, 2006 2:26 PM:

>>I believe the unseating of oil (short of a worldwide Hubbert's Peak) requires battery technology to bring in all the electric power sources as competition to liquid fuel.

So ultimately, there are three forces working against oil-exporting tyrants :

1) Biomass Ethanol
2) Coal liquifaction
3) Battery technology for cars.

If *any* of these three happen, the likes of Iran, Saudi Arabia, etc. will take massive financials hits (which is what I hope for). Sure Biomass Ethanol has other negatives, but it would displace oil.

The odds of none of these 3 becoming viable by 2015 seem slim, in my opinion. When there are at least three forces working against you, you have a problem.

BTW, what do you think of the Tesla Roadster? They claim they will have a 4-door sedan by 2009, and if that technology can move down a cost-curve, it might reach middle-class pricepoints by 2016. What do you think of that?

Randall Parker said at December 20, 2006 7:43 PM:

TTT,

I'd add oil shale to your list. See my post Shell Oil Shale Extraction Technology Economically Viable? for the details.

But, yes, you have the broad outline.

As for future viability: There's big money in energy. People have been chasing various technologies for decades. Some of them are going to reach maturity. I'd put viable batteries ahead of solar photovoltaics on a timeline.

The Tesla Roadster does not matter. The demand for batteries for hybrids and plug-in hybrids is providing a far bigger incentive for battery developers to come up with better battery technology.

TTT said at December 22, 2006 7:41 PM:

How long do you think it would take for all of the electricity in the US to be from solar, wind, and nuclear, so that no more fossil fuels are used for electricity? Or would this not happen in the forseeable future?

Randall Parker said at December 23, 2006 8:04 PM:

TTT,

I think a shift to solar, wind, and nuclear as source of even half of electriciy is a distant prospect.

Solar is too expensive. There's always the possibility of a sudden big breakthrough. Hard to forecast that. But even suppose that the photovoltaics cost breakthrough happened. Suppose the cost per kwh suddenly became 2 cents. We'd still need other electric sources for when the sun does not shine since we do not have cheap ways to store electricity.

Wind is cheaper than solar. But the wind does not always blow and it costs more than nuclear. Nuclear costs more than coal.

We could shift to nuclear now if electric generators were banned from releasing carbon dioxide into the atmosphere. But I see such a ban as a distant prospect. Even carbon taxes will come slowly and small amounts.

Since I do not foresee a big turn-around on the issue of carbon dioxide emissions taxes I think that nuclear, wind, and solar will have to compete on cost. Wind is making some in-roads because California and a few other states are mandating no carbon emissions from some percentage of total generated electric power (15%? 20%? something like that - I have a post about it) gradually in the 2010s. Also, wind equipment is getting cheaper and wind makes sense in some areas with highly dependable high speed wind. But wind is going to remain a bit player compared to coal.

Again, two things could drive a shift to non-fossil fuel electric:

1) High taxes on carbon dioxide emissions.

2) Cost breakthroughs.

I expect #2 to happen eventually. I expect #1 in smaller doses. But not big enough to make the non-fossil fuel energy sources into primary energy sources.

TTT said at December 24, 2006 3:59 PM:

Randall,

I think a shift to solar, wind, and nuclear as source of even half of electriciy is a distant prospect.

Wait, so you are not optimistic on there being major changes in the sources of electricity production?

Also, you said a battery breakthrough would bring electricity in competition with oil, but that type of breakthrough could be very far off.

And, ethanol is not a scalable solution to oil.

So, after combining this whole discussion, it appears that you feel that there will probably not be major shifts in the proportion of energy provided by oil (for cars) and coal (for electricity), by 2015. A major change is possible, but not probable. Is this a correct assessment of what you expect between now and 2015?

Randall Parker said at December 24, 2006 5:48 PM:

TTT,

2015 is 8 years away. Currently most planned new electric generation capacity in the US is coal and most of the existing electric generation capacity is coal. New nuclear plants are now planned by several US utilities and some will get built. But nuclear will remain a minority of new construction until either a breakthrough in nuclear plant costs or much tougher emissions controls on coal.

Even if the regulatory environment shifted greatly 4 years from now my guess is the existing coal plants would get retrofitted rather than replaced with nuclear. The cost of retrofit would probably be less. So only a majority of new construction would be nuclear. Hence my statement that nuclear as the majority source of electric isn't going to happen soon.

Given a large enough cost breakthrough in wind or solar the coal plants could shut down when the wind blows or the sun shines. But coal plants would still continuing to operate the rest of the time.

I expect regulations on coal plants to get tougher during the 2010s. I do not know how tougher how quickly.

I expect the cost of nuclear to fall. Again, I do not know how far and how fast.

I think photovoltaics have better prospects for big price drops than wind or nuclear does. Solar costs more than wind now but will eventually be cheaper than wind. Though I do expect advances in wind power to lower wind power costs.

I expect by the 2020s solar photovoltaics will be very cheap and electric cars will be commonplace and photovoltaics will be used to charge cars and supply peak power. But solar won't solve the baseload power problem.

Parenthetically, the base load demand will grow more rapidly than peak demand. That's been the pattern in recent years. Big computer server farms run 24x7 and are boosting demand for baseload power.

TTT said at December 24, 2006 6:26 PM:

I expect by the 2020s solar photovoltaics will be very cheap and electric cars will be commonplace and photovoltaics will be used to charge cars and supply peak power. But solar won't solve the baseload power problem.

So the end of oil, and possibly the end of biomass fuel for cars, is in the 2020s, as per this. But coal for power appears to be a tougher obstacle than oil (even though most people believe the opposite). At least the US is self-reliant in coal.

So a scenario could be :

1) Oil prices continue to hover between $60 and $100 between now and 2010.
2) Cellulose breakthroughs permit biomass liquid fuel to displace oil from 2011 to 2020, allowing up to 50% of oil consumption to be replaced with biomass by 2020, but with a lot of land consumed by biomass crops.
3) By the 2020s, battery technology, with photovoltaics, permit fully electric cars to become viable, replacing both the biomass/ethanol demand AND the remaining oil demand, by 2025-30.
4) In 2025, coal is still used for a good portion of electricity generation, with wind, nuclear and solar making respectable contributions.

What do you say?

Randall Parker said at December 24, 2006 8:54 PM:

TTT,

I see two problems with your scenario:

1) Not enough suitable farm land.

2) Rapidly rising Asian demand for liquid fuel and electric power.

Think about another billion people starting to drive in the next 25 years. It is mind boggling. Seems to me that we need big technology breakthroughs in solar, nuclear, and battery technology. All shorter vehicle trips would have to switch to electric and biomass liquid fuels would be used for longer trips. But even under that scenario the amount of liquid fuel needed for airplanes, long haul trucks and other longer trips still seems enough to keep the Arabs in the oil biz.

The World Bank sees a huge growth in the world's middle class between now and 2030:

Good news for U2’s Bono – the number of people in extreme poverty will be halved over the next 25 years. That’s faster than the previous 25 years (1980-2005) and probably the highest in history.

The projection is made in a new World Bank report, 'Global Economic Prospects 2007: Managing the Next Wave of Globalization,' which attributes this to rapid growth of developing country economies rather than to western taxpayer-funded aid schemes as urged by a tax-dodging popular musicians.

...

The key to the report's long-term projections is the emergence of a 'global middle class' - defined as those with an annual per capita income between the average in Brazil and in Italy (about $US4-17,000 respectively).

‘By 2030, 1.2 billion people in developing countries – 15 per cent of the world population - will belong to [this class], up from 400 million today. [It] will enjoy access to international travel, purchase automobiles and other advanced consumer durables, attain international levels levels of education, and play a major role in shaping policies and institutions in their own countries and the world economy,’ the report says.


ExxonMobil sees strong global energy demand growth to 2030:

ExxonMobil's shift in the projected gas-coal balance drew some attention during a 75-minute conference call with analysts. ExxonMobil Tuesday said it expects coal use to grow by an annual rate of 1.6% a year through 2030, little changed from the 1.7% growth outlined in its 2004 forecast. But the oil giant sees natural gas consumption rising by 1.7% annually through 2030, a sharp reduction from the 2.2% annual growth forecast just two years ago.

Still, Spellings noted that the global resurgence of coal is partially contingent on the regulatory regime surrounding greenhouse gases. While Spellings refused to speculate on the chances of global mandatory emission limits, he said the prospect of additional regulation is a "huge question mark" regarding growth in coal.

The 2006 version of the company's annual energy forecast also points to marginally lower projections for overall energy consumption growth. The oil giant now projects annual consumption growth of 1.6% through 2030, when overall energy use will hit about 324 million barrels of oil equivalent per day, according to a graphic presented Tuesday.

The 324 million barrels is an amount of energy from all sources but expressed as how many barrels of oil it would take if all that energy came as oil. ExxonMobil expects oil production (including, I suspect, conversion from coal and shale) to rise from 85 million to 115 million barrels per day.

Currently the United States uses about a quarter of that 85 million barrels a day. But the US slice is shrinking in percentage terms as China's portion rises rapidly.

The US Department of Energy's Energy Information Administration expects some growth in ethanol production but for ethanol to remain a small player.

While the EIA boosted its estimates of U.S. ethanol consumption by 21% to 14.6 billion gallons by 2030, only 200 million gallons would be sold as E85, a mix of 85% ethanol and 15% gasoline. EIA Administrator Guy Caruso said the forecast was based on distribution bottlenecks and a lack of a clear price advantage for E85 over regular gasoline.

To put that in perspective the US currently consumes over 140 billion gallons of gasoline per year. That ethanol per gallon has less energy than gasoline. So their estimate is more like 10 billion gallons of gasoline equivalent. That's a big increase from today's level but still small. Currently the US is making about 9 million barrels of ethanol per month which works out to less than a tenth of what the EIA is projecting for 2030. But the increase of a whole order of magnitude will leave US ethanol production still over an order of magnitude below current gasoline demand, let alone 2030 demand (all this in the United States only).

I keep arguing we need to greatly accelerate the rate of advance of energy technologies. The industrialization of the world is going to boost coal, oil, natural gas, tar sands, and oil shale production. We need cheaper nuclear, much cheaper solar, and really great batteries.

TTT said at December 25, 2006 1:43 PM:

We need cheaper nuclear, much cheaper solar, and really great batteries.

Sounds like there is not much chance of this happening to a degree that it makes a big difference, any time soon.

So by 2030, oil for cars and coal for US electricity will still be the dominant sources..


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